Performing Preventive Maintenance Tasks
To avoid common server problems, review the following:
Preventing Memory Problems
- Make sure you have adequate memory installed on the system.
- Modify the NET.CFG file to load only necessary drivers.
- Modify the CONFIG.SYS file to load only necessary drivers.
- Check the AUTOEXEC.BAT and CONFIG.SYS files to make sure no memory managers, such as HIMEM.SYS or EMM386.EXE, are being loaded and that there is no DOS=HIGH statement in either file. Make sure no DOS device drivers are being loaded.
For information about freeing up memory on a server, see Freeing Server Memory Temporarily.
Preventing Power Supply Errors
An inconsistent power source is the most common cause of hardware problems. It also produces the most devastating results.
Power outages cause workstations, network servers, print servers, and backup devices to reboot. When this happens, all information stored in RAM is lost and sometimes hardware is damaged.
Power spikes and brownouts can also cause a variety of hardware errors.
You can have reliable network performance only if you plan for power outages and fluctuations and protect against them. The following tips can help you do this:
- Add a dedicated power feed and ground line from your breaker box to critical equipment. Make sure the ground line connects to earth ground.
- Install an uninterruptible power supply (UPS) or a standby power system (SPS) to provide power to critical equipment for 15 minutes after a power outage.
The capacity of such power supplies is limited, so you might not want to plug nonvital hardware (such as monitors or printers) into the UPS or SPS line.
- Train users to save data and log out of the network when the power goes out. Then you can bring down the NetWare server in an orderly manner without forcing users off the system while the server is running on UPS or SPS power.
- Install a surge suppressor or power conditioner on all power lines that are used by computers. Many UPS and SPS devices already have this feature.
- Do not allow anyone to plug fans, printers, copy machines, vacuum cleaners, or other motor-driven appliances into the dedicated line or into any power line with computers.
Insert "dummy plugs" into open outlets to prevent people from plugging such appliances into computer power sources.
Preventing Static Electricity Problems
An electrostatic discharge (ESD) must equal about 3000 volts before you can feel it, but sensitive electronic components such as microchips and circuit boards can be damaged by ESDs of as little as 20 or 30 volts. These small discharges do not cause a component to fail immediately, but can cause the component to degrade over time and fail at a later date.
We recommend that you take the following precautions to protect electronic components from electrostatic discharge:
- Ground yourself and your equipment with a proper wrist strap and mat before working on computers and computer boards. Test grounds daily to make sure they have not become loose or intermittent.
WARNING: Do not use a wrist strap when working on monitors! They can carry a large voltage that can reach you through the strap.
- Never touch components or integrated chips by their electrical leads.
- Do not allow anyone to touch you when you are working on boards that contain integrated circuits. They might cause a static charge.
- Transport and store boards and integrated circuits in static-shielding bags, usually grey-silver in color. The bags must be in perfect condition because tiny pin holes will defeat their purpose. Anti-static bags (blue or pink) do not shield their contents from external static fields and should not be used.
- Keep nonconductors, such as polyester clothing and plastic, away from open computers and components. Nonconductors are a source of static charges.
- Never place components on any conductive surface, such as metal.
- Keep the humidity of any area where you have open computers at 70 to 90 percent. Static electricity problems are more likely to occur in low humidity.